There are numerous applications in which a float activated shut off valve is used, In such applications, a valve member is carried by a float against a valve seat when a liquid level reaches a predetermined height in a vessel or tank. By way of example, in the oil industry a quantity of natural gas is invariably produced by an oil well. It has become a common practise to use that natural gas. One way that the natural gas is used is as a fuel to operate on site equipment. Natural gas direct from the well is "wet", that is to say it contains quantities of condensible components which can form liquids during extraction and processing, including water, sulfides and higher hydrocarbons. The liquids may form as a separate phase or may be entrained in the natural gas in a finely dispersed state. The liquids which are present in the natural gas render it unsuitable for use as fuel, for wet gas can damage equipment, due to the presence of sulfides and higher hydrocarbons. The natural gas is, therefore, routed through a fuel gas scrubber to remove liquids. A fuel gas scrubber is a vessel that has a mixed gas and liquids inlet, a gas outlet and a liquid outlet. The gas outlet is in a normally open position, with gas being drawn for use, as required. The liquid outlet is in a normally closed position, with the result that liquids gradually accumulate within the vessel. The accumulated liquids are supposed to be periodically drained from the vessel via the liquid outlet. A float activated shutoff valve is used in the fuel gas scrubbers to shut off the flow of fuel gas should the liquid in the vessel rise above the predetermined level.
The float activated shutoff valves that have been used in fuel gas scrubbers consist of a valve member housing in which is positioned a valve member. A float is suspended from the valve member by means of a rod. The arrangement resembles a pendulum except that the movement is up and down along the axis of the rod. These float activated shutoff valves have experienced numerous problems. Fluids flowing into the vessel through the mixed gas and liquids inlet tend to strike the float that is hanging at the end of the rod. The force of the in flowing fluids acting against the float has been known to bend the rod, resulting in failure. The force of the in flowing fluids acting against the float has been known to detach the float from the rod, resulting in failure. The force of the in flowing fluids acting against the float has been known to physically damage the float, resulting in failure.